A sump for collecting sewage. Cleaning of industrial sedimentation tanks. Static and dynamic filters

Waste and sewage treatment systems use a water sump, which is designed to ensure that large fractions are deposited at the bottom of this device, and oil products are removed for further disposal. In other words, this facility carries out mechanical and biological purification Wastewater.

From the name of this device it is clear that the sand trap retains sand and small particles of waste. It is the primary septic tank and is located at the beginning complex systems wastewater treatment. If the sand is not removed from the water, then subsequent elements will be clogged with it.

The work of the sand trap is carried out using several methods:

• rectilinear horizontal flow of water flow;
• horizontal circular flow;
• vertical current directed upward;
• helical flow or translational-rotational.

All these methods characterize the movement and direction of water flow.

The helical flow can be generated by compressed air.

At the beginning of the sand trap, special gratings are placed in order to trap large mechanical particles.

The horizontal sump has an inclined bottom. At the same time, the flow of water at the bottom slows down significantly, and the sand, which is located in the lower part of the flow, settles to the bottom. In the future, the sand is removed by hydraulic elevators.

Static type sump

To remove numerous oil contaminants from the water, there are static sedimentation tanks, the operation of which is rather slow. Typically, this process takes up to two days. Wastewater flows very unevenly, so this method of treatment requires a large reservoir.

Without pumping, it is not easy to separate oil impurities and other products of oil distillation from water. To speed up the process, two or more buffer reservoirs are used. First, they are filled, then, for a certain time, there is a settling phase. After that, the polluted substances are pumped out.

Buffer reservoirs are designed to reduce the concentration of pollution and partially load the main reservoir in case of uneven flow of wastewater.

The main advantage of this method is the high degree of tightness of reservoirs.

Dynamic settling tanks for oil

With a vertical arrangement of tanks, sedimentation of effluents can occur in static and dynamic modes.

Dynamic settling tank: 1 - oil trap body, 2 - hydrogelator, 3 - oil layer, 4 - oil gathering pipe, 5 - baffle, 6 - scraper conveyor

In the latter case, the settling tanks may be smaller. At the same time, they are filled with wastewater and pumped out simultaneously. The advantage of this method is that only one reservoir is sufficient.

But a dynamic sump requires equipment that controls effluent and oil levels. Automatic elements control the level by shutting off the inlet and outlet flow in the tank. Also, as part of such devices, there are means and devices for removing oil products, which are located at the top of the tank and sand and solid parts of the waste at the bottom.

In order to better and faster separate oils from other wastes, an active substance is added that works effectively with the surface level of contamination.

Sand sediment is removed through drainage pipes, which are made by perforation. And oil products are removed by a special pipe, which is placed in one position, and the water level is adjusted to fit it by draining. This work is controlled by automatic level sensors.

Waste water settling ponds

The creation of settling ponds in the form of separate ponds is the most in a simple way wastewater treatment. Heavy waste fractions settle to the bottom, while lighter fractions float to the surface.

However, this way has major disadvantages:

• big square;
• soil and air pollution;
• high cost of disposal;
• the influence of weather and atmospheric conditions on the degree of purification.

Therefore, ponds have recently been used rarely or on large enterprises. Their use causes irreparable damage to the environment.

Options for the device of dynamic sedimentation tanks

Dynamic settling tanks differ in the type of pollutants:

• sand,
• fuel oil,
• oil,
• petrol,
• butter.

In the direction of water flow, they can be horizontal or vertical.

Horizontal settler functions as follows. Heavy waste sediment is moved to a separate location and removed using pumps or hydraulic elevators. And light products floating on the surface are removed by transverse trays.

Settling tanks of vertical type have a cone-shaped bottom from which sediment is removed. In this case, the flow of water goes from bottom to top.

round in shape. The flow of water can move from the center or from the edges. The size of such a device can reach 100 meters in diameter.

If water begins to move from the center of the structure to the edges, then a relatively high speed is required for effective cleaning. If the water flow is directed from the edges to the center, then the degree of wastewater purification increases.

Thin layer settling tanks

The large depth of the sump does not allow oils and other substances of oil refining to quickly float to the surface. Therefore, for greater efficiency, thin-layer sedimentation tanks are used, in which the wastewater layer is minimal.

They are divided into two types:

• tubular settling tanks;
• plate type devices.

The main part of the tubular sump is a pipe with a diameter of 2.5 to 5 centimeters and a length of one meter. Its size depends on the type of pollution and the characteristics of the water flow. Such devices come with a large and small inclination of the working parts.

Settling tanks with a slight slope are used to treat wastewater from solid impurities at their low concentration. The degree of purification reaches 80%. However, the tubular sump needs to be periodically cleaned of accumulated sediment. Therefore, a second device is needed. One sump is in a state of cleaning, while the other is working at this time, and vice versa.

Devices with a large slope do not need to be cleaned, in which the sediment is removed naturally due to the large slope of the pipe. If the cleaning time needs to be increased, then devices with a pipe up to three meters, which is made of plastic, are used.

Plate-type devices contain plates that are installed in parallel. A stream of sewage passes between them.

According to the type of construction, there are lamellar sedimentation tanks of the following types:

• direct-flow devices in which sediment and purified water move in a parallel direction;
• countercurrent devices, where sediment and water move towards each other;
• devices with perpendicular direction of the plates.

Counterflow sedimentation tanks are the most efficient.

Thin-layer sedimentation tanks contain basic elements that are made of plastic. This material is much lighter than metal and is resistant to corrosion and aggressive chemical environments. These devices have one significant drawback - for their effective work wastewater is required, which is previously cleaned of sand and large fractions of oil.

If the drains contain a lot of clots of oil and oils, then the tubular and lamellar sedimentation tanks will fail.

Therefore, there are two-tier settling tanks that combine several functions in their work, in them at the same time:

• sewage is settled,
• fermentation of organic matter takes place
• the precipitated precipitate is compacted.

Structurally, these devices are a cylinder with a cone-shaped bottom. On top there are troughs in which solid and heavy fractions are deposited, and at the bottom there is a chamber for sludge. In this chamber, the waste is decomposed by bacteria. Waste sludge is then removed from the chamber through a special pipe.

The decision on which device to choose and how to make a sump depends primarily on the nature and degree of wastewater pollution. In private homes, the composition of wastewater is much better and simpler. Therefore, settling tanks are used only for the sedimentation of large fractions of waste. These devices play an important role in water purification and prevent pollution of the area by substances harmful to humans.

A bunch of industrial enterprises have production wastes that cannot be disposed of by disposal into environment. Such hazardous substances are subject to storage in special facilities - settling tanks, where they are not capable of causing significant damage to the environment. But, no matter how large industrial sedimentation tanks are, sooner or later they are filled, and production processes at enterprises stop. Stopping work threatens with significant costs, as well as the loss of part of the client base.

To solve the problem of overflow will allow measures to cleaning of industrial sedimentation tanks. As a rule, such work is carried out by pumping waste with powerful slurry pumps into new sedimentation tanks, or areas intended for this. With the help of successively installed pumping stations, liquid waste pumping takes place along a pre-prepared pipeline at a distance of up to several tens of kilometers. The intake of sediments is carried out from the shore, by the first slurry pump, or with the help of a suction dredger located in the sump.

To carry out work on sump cleaning You can contact Hydrostroy. Thanks to our extensive experience in the field of hydromechanized soil transportation, we are able to organize the pumping and supply of liquid waste at a distance of tens of kilometers from the storage point.

By contacting us, you can order the following works:

• Cleaning of industrial sedimentation tanks of any volume;
• Waste reduction for the planned production cycle;
• Creation of soil alluvium maps;
• Installation of ground pipelines for periodic waste disposal;
• Carrying out technical supervision and general management of cleaning operations.

Disposal of industrial waste- this is one of the main directions of the organization Gidrostroy. The presence of a serious division of pumping equipment, as well as significant experience in the field of hydromechanization, allows us to produce sump cleaning any size, any degree of complexity.

K category: Sewage treatment

Settling tanks for wastewater treatment

Sedimentation tanks are used for preliminary wastewater treatment, if, according to local conditions, their biological treatment is required, or as independent structures, if, according to sanitary conditions, it is quite sufficient to isolate only mechanical impurities from wastewater.

Depending on the purpose, settling tanks are divided into primary, which are installed before the biological wastewater treatment facilities, and secondary, which are installed after these facilities.

According to their design features, sedimentation tanks are divided into horizontal, vertical and radial. Clarifiers can also conditionally be classified as settling tanks, in which, simultaneously with settling, wastewater is filtered through a layer of suspended solids.

The type of settler (vertical, radial, with a rotating collection and distribution device, horizontal, two-tier, etc.) must be selected taking into account the accepted technological scheme wastewater treatment and sludge treatment, capacity of facilities, construction sequence, number of units in operation, site configuration and topography, geological conditions, groundwater level, etc.

Rice. 1. Horizontal sump made of precast concrete 1 - pipeline for the removal of raw sediment; 2 and 4 - trays with a cross-sectional area, respectively, 800X 900 and 600X900 mm; 3 and 14 - siphons for supplying initial waste water; 5 - inlet holes; 6 - scraper cart; 7 - fat collecting tray; 8 - weir rib; 9 - front trolley; 10, 11 - fat cells; 12 - emergency siphon; 13 - pipeline emptying; 15 - gates 400X600 mm; 16 - siphon for draining clarified water

Rice. 2. Scheme of particle settling in a horizontal settling tank

Sometimes settling tanks are calculated according to the load, i.e. according to the amount of waste liquid, m3, per 1 m2 of the surface of the water surface of the sump in 1 hour. This value is assigned according to the operation data of similar sumps that provide a more or less satisfactory clarification effect. Typically, the load is 1-3 m3 / h per 1 m2 of the surface of the sump.

In addition to the dimensions of the flow part of the settling tanks (I, L, B), within which suspended solids settle, it is also necessary to determine the volume of the settling part of the settling tank. The amount of sediment in the primary settling tanks for domestic wastewater is 0.8 l/day per person. The moisture content of the discharged sludge depends on the methods of its removal: with gravity sludge removal, it is assumed to be 95%, and for mechanized sludge removal, 93%.

To accumulate the precipitated sediment and periodically unload it, pits are arranged at the beginning of the sump, the volume of which depends on the design of the sump and methods for removing sludge. The most common method is squeezing out the sediment under a hydrostatic head of water equal to 1.5 m. In some cases, the precipitate is removed by pumping it out with plunger pumps. The volume of the sedimentary part of the settling tanks is taken equal to the two-day volume of the precipitated sediment (with mechanized sediment removal, the volume of the sedimentary part can be taken equal to the 8-hour volume of the precipitated sediment). In order for the sediment to slide by gravity to the pits, the bottom of the sump is given a slope of at least 0.01. Horizontal settling tanks are designed with scraper mechanisms for raking sediment to pits.

Vertical settling tanks are round or square tanks with a conical or pyramidal bottom. Vertical settling tanks are usually provided at stations with a capacity of up to 50,000 m3/day, and more often up to 20,000 m3/day, and at low groundwater levels.

Waste liquid is supplied to the bottom of the working part of the sump through the central pipe (Fig. 3). After leaving the pipe, the waste liquid moves from the bottom up to the drain channels, through which it enters the outlet tray. During the movement of the waste liquid through the sump, suspended solids fall out of it, the specific gravity of which is greater than specific gravity water.

Prof. S. M. Shifrin, based on the results of numerous experiments and theoretical studies, proposed new method calculation of vertical sedimentation tanks. Observations of the distribution of the waste liquid over the sump showed that the liquid, leaving the gap between the socket of the central pipe and the baffle shield, moves radially towards the walls of the sump, and then rises up along the walls at relatively high speeds. Suspended substances fall out on the horizontal path of the liquid from the center of the sump to the periphery due to the spreading of the jet and a decrease in the speed of movement. The finer the particles that must be separated from the waste liquid, the greater must be the radius of the sump, which is the main design value.

Rice. 3. Vertical sump with a diameter of 9 m from precast concrete 1 - sludge outlet; 2 - release of floating substances; 3 - central pipe with a reflective shield; 4 - drainage chute; 5 and 6 - outlet and inlet trays

Rice. Fig. 4. Dependence of the clarification effect E in vertical settling tanks on the minimum hydraulic size of the settled particles "o" and the initial concentration of suspended solids in the waste liquid C (a) and a graph for calculating vertical settling tanks

When calculating settling tanks according to the method of prof. S. M. Shifrin, first, according to the required effect of clarification at a given concentration of suspensions in wastewater, they find according to the graph (Fig. 4, a) the hydraulic size and particles that should be retained in the sump. Then, according to the found hydraulic fineness according to the graph (Fig. 4.6), the radius of the sump r is determined depending on the average speed of the entry of the waste liquid into the sump, taken equal to 1.2 m / s. The central tube diameter d is calculated from a velocity of 30 mm/s. The length of the pipe and the height of the cylindrical part of the sump equal to it is assumed to be at least 2.75 m.

Rice. 5. Vertical settling tank with descending-ascending flow 1 - receiving chamber; 2 - feed tray; 3 and 4 - pipeline and receiving funnel for removing floating substances; 5 - gear spillway; 6-reflective visor; 7 - distribution tray; 8 - tray for collecting clarified water; 9 - outlet pipeline; 10 - sump; 11 - annular semi-submersible partition; 12 - silt pipe

Rice. 6. Vertical sump with a peripheral inlet device 1 - supply pipe (or tray); 2 - water distribution tray of variable section; 3 - wind guide wall; 4 - annular drainage tray; 5 - pipeline for the removal of clarified water; 6 - reflective ring; 7 - pipe for the release of sediment; 8- collection of floating substances

Rice. 7. Primary radial settling tanks 1 - sludge scraper; 2 - distribution bowl; 3 and 7 - inlet and outlet pipelines; 4 - raw sludge pipeline; 5 - grease collector; 6 - pumping station

The volume of the sedimentary chamber of vertical settling tanks is determined in the same way as for horizontal settling tanks. The sediment is removed by gravity (under the hydrostatic head of the water column) through a sludge pipe lowered to the base of the sump. The lower part of the sedimentary chamber is made conical or pyramidal with an angle of inclination of the walls to the horizon of 50 ° to create favorable conditions for the sliding of the precipitated sediment.

Clarified water is discharged through a drain tray (gutter) located along the perimeter of the sump. At a distance of 0.3-0.5 m from the gutter, a semi-submersible board is usually installed, which traps floating substances. For settling tanks with a diameter of 6 m or more, prefabricated gutters are arranged not only along the periphery, but also radially, which improves the conditions for distributing water in the settling tank and increases the effect of its operation.

Vertical sedimentation tanks are made of reinforced concrete. The effect of liquid clarification in such settling tanks practically does not exceed 40%.

Of interest is the design of a vertical settling tank with a descending-ascending flow of wastewater (Fig. 5). Instead of a central pipe, this sump has a large diameter semi-submersible baffle. The water inlet is made through a gear weir. The reflective visor changes the direction of water flow from vertical to horizontal. Then the flow rises, the water overflows into the collection tray and is discharged by a pipe. This design of the sump provides an efficiency of retention of suspended solids of 60-70%. The ratio of the descending and ascending flow areas is assumed to be 1:1. The height of the semi-submersible partition is 2/3 of the height of the flow part of the sump.

In a vertical settling tank with a peripheral inlet designed by VNII VODGEO (Fig. 6), waste water is supplied to the distribution peripheral tray, and from it to the annular zone between the settling tank wall and the jet guide wall. At the bottom of the annular zone is a reflective ring. The clarified water is collected by an annular gutter with serrated weirs. The speed of water movement in the water distribution tray is 0.4-0.5 mm/s. The specific load on the serrated weir is 6 l/(s-m).

Radial settlers. A variation of the horizontal settling tank is the radial settling tank (Fig. 7), which is a round, shallow reservoir in which water moves from the center to the periphery. Radial settling tanks are arranged with the release of water from below or from above; In both cases, water enters the sump through the central pipe, and the clarified water drains into a circular chute, from where it is discharged through pipes or trays. The sediment that has fallen to the bottom is raked to the center by scrapers fixed on a movable truss and enters the pit, from which, under the pressure of a 1.5 m high water column, it is removed through pipes or sucked off by plunger pumps.

Radial sedimentation tanks are mainly used in large wastewater treatment plants. In particular, such settling tanks have been built at the Lyuberetskaya and Kuryanovskaya treatment plants in Moscow. The diameter of the sedimentation tanks can be different (from 18 to 54 m). These settling tanks can be calculated according to the load, taking equal to 1.5-3.5 m3 per 1 m2 of surface in 1 hour. The duration of settling, depending on the method of subsequent biological treatment, ranges from 0.5 to 1.5 hours. % for gravity removal and 93% for pump removal. Typically, radial clarifiers are arranged in blocks of four clarifiers.

They also design and build radial sedimentation tanks with a peripheral supply of wastewater (Fig. 8). The water distribution chute, located on the periphery of the sump, has a constant width and a variable depth, since inlet holes of different diameters are placed at different distances from each other in the bottom of the chute and thereby ensure a constant forward speed of water movement in the chute, so sediment does not fall out in the chute. The liquid flow is directed to the lower zone of the sump, and then to the central zone and up to the drainage annular trough. This movement of the flow creates favorable conditions for the precipitation of suspended solids. The sediment is collected by a collector and discharged outside the sump through a pipe.

To collect and remove the floating coarse impurities, two hoppers are provided, one of which is installed in the central part of the sump, and the second - in the annular zone. The clarified water is discharged from the central annular tray with a double-sided spout or through slotted holes in the centrifugal pipe.

Settling tanks with a peripheral water inlet and with the same settling time provide a 1.2-1.3 times greater cleaning effect than conventional radial settling tanks; with the same cleaning effect, their throughput increases by 1.3-1.6 times, depending on the concentration of the source water. MosvodokanalNIIproekt developed designs for primary settling tanks with a peripheral water inlet with a diameter of 24 and 30 m.

Rice. 8. Radial sump with a peripheral outlet with a diameter of 18 m 1 - inlet channel; 2 - pipeline for removal of floating substances; 3 - outlet pipeline; 4- shutter with a movable weir for the release of floating substances; 5 - jet guide tubes; 6 - distribution tray; 7 - semi-submersible board for retaining floating substances; 8 - silt pipe

Rice. 9. A sump with a rotating collection and distribution device 1 - supply pipeline; 2 - air locks; 3 - central bowl; 4 - assembly and distribution device; 5 - peripheral drive; 6 - scrapers; 7 - outlet pipeline of clarified water; 8 - silt pipeline; 9 - flooded tray; 10 - vertically suspended blades; - spillway; 12 - semi-submersible board; 13 - slotted bottom; 14 - curvilinear partition; 15 - fat collector chamber; 16 - the direction of the inlet of waste water; 17 - direction of movement of the collection and distribution device

The original design of a radial sump with rotating water distribution and collection devices, proposed by prof. I. V. Skirdov (Fig. 9). The design of the settling tank is such that the bulk of the water in it is in the flow and therefore the rapid settling of suspended solids is ensured. Distribution and collection of clarified water is carried out using a rotating chute, divided by a longitudinal partition. The distribution tray has jet vanes and a slotted bottom through which heavy particles fall.

The walls and bottom of the gutter with a flooded spillway are watertight. The water from the tray is drained by means of a siphon into the discharge chute. In the catchment tray at the bottom there is a guide cap. Bandwidth The settling tank of this design is 1.5 times larger than a typical radial settling tank with the same clarification effect. The depth of the sedimentation zone is 0.8-1.2 m, the height of the neutral layer is 0.7 m.

Soyuzvodokanalproekt has developed projects for sedimentation tanks with a rotating collection and distribution device with a diameter of 18 and 24 m.

Thin-layer settling tanks have a water distribution, settling and catchment zones, as well as a sedimentary zone. The settling zone is divided by shelves (or pipes) and settling takes place in the space between the shelves up to 15 cm high. A number of designs of thin-layer sedimentation tanks are known.

In a thin-layer sump, the following schemes for the movement of water and precipitated sediment are possible:
1) cross - when the sediment moves perpendicular to the direction of flow;
2) countercurrent - when the sediment is removed in the opposite direction to the flow;
3) direct-flow - when the directions of flow and sediment are the same.

The most effective are thin-layer settling tanks with a countercurrent flow of phases - water and sediment. The sediment slides into a sludge pit, from which it is periodically removed. Floated substances are collected in the bosom between the sections and removed by the tray. Thin-layer settling tanks are usually used to clarify wastewater containing suspended solids of a homogeneous composition in relatively small concentrations. Sometimes they are used as the second stage of mechanical cleaning.

Rice. 10. Thin-layer tubular settler 1 - supply distribution pipelines; 2- distribution gap; 3 - plastic tubular blocks; 4 - catchment gap; 5 - trays for collecting clarified water; 6 - sinuses for collecting floating substances; 7-turn pipes for removal of floating substances; 8 - capacity; 9 - pits for collecting and compacting sediments; 10 - pipelines for the release of sediment

Rice. Fig. 11. Dependence of the exponent pi on the initial concentration of mechanical pollution in urban wastewater with different settling effects

By design, thin-layer sedimentation tanks are vertical, horizontal and radial. They have a water distribution and drainage area and a zone of shelf or tubular elements. The flow velocity in shelf elements is 5-10 mm/s, and in tubular elements up to 20 mm/s. The height of the thin-layer space is 1-2 m. Thin-layer blocks made of plastic, steel or aluminum have a slope of 45-60°.

In a thin-layer tubular counterflow sump (Fig. 10), wastewater is fed through distribution pipelines into wedge-shaped slots. Then the water is clarified in tubular blocks and collected by catchment slots. The precipitated sediment slides into silt pits, from where it is removed under the action of hydrostatic pressure. Floating substances are removed using rotary pipes.

- Sumps for wastewater treatment

Primary clarifier is a construction of a mechanical treatment unit designed for gravitational settling of finely dispersed contaminants, mainly organic, and, as a result, a decrease in BOD and COD. The shape in plan is round or rectangular. The number of settling tanks is determined by calculation and must be at least two.

Primary clarifiers can be:

1. Horizontal;
2. vertical;
3. Radial.

These settling tanks differ in the movement of the flow of treated water.

Primary horizontal clarifier- This is a rectangular tank, consisting of several corridors. Vertically, the structure can be divided into a working part (where sedimentation takes place) and a silt part (where sediment is collected). Between these conditional zones there should be a distance of at least 0.4 m. At the beginning of the horizontal sump, a pit is arranged where the sediment is raked (with scrapers) or washed off. It is removed from the pit by hydraulic elevators or pumps. The disadvantage of this type of structure is a large area. Plus - high efficiency.

Vertical primary clarifier- This is a cylindrical structure with a conical bottom. The purified water is supplied from above into the pipe, which is located in the center of the structure. Under the pipe is a reflective shield. Hitting it, the water changes direction and moves from bottom to top. For better flow distribution, the central pipe is made with a broadening at the lower end. The clarified water is collected in collection trays, which are located on the edge of the tank. The sediment accumulates in the conical (sludge) part of the sump and is removed from there under the action of pressure (hydrostatic) through the sludge pipe. The disadvantages of the design are the great depth and the impossibility of using it with a treatment plant capacity of up to 10,000 m3 / day.

Radial primary clarifier – special case vertical sump. The difference is that in this type of structure, water moves from the center to the periphery, and not from the bottom up. Therefore, the design is different. The radial settler, like the vertical one, is round in plan. But the wastewater supply pipe is located below. The flow is also supplied to the center, here the highest speeds are observed, which decrease as they approach the collection trays (periphery). Sediment accumulating at the bottom is moved by scrapers to the sludge pit (in the center), from where it is removed by a centrifugal or plunger pump. The disadvantage of the design is low efficiency. Plus - not high cost. Varieties of this type of clarifiers are a clarifier with a peripheral inlet and with rotating water distribution and collection devices.

All types of settling tanks are equipped with devices for collecting floating substances.

Based on the mode the work of primary settling tanks they are divided into:

1. Intermittent action (contact)
2. Continuous action (flow-through)

When choosing the type of sump, the economic factor, the composition of effluents, geological and hydrogeological conditions, terrain conditions, estimated costs, etc. are taken into account.

If the purification efficiency is not sufficient, then one more purification stage can be added or the structure design can be intensified. In this area, much attention is paid to the system of wastewater inlet to buildings, since the distribution of the flow has a great influence on the treatment. In horizontal settling tanks, for example, perforated shields are used for this, located at the beginning of the tank (1/3 of the length from the input); in vertical - a reflective shield. It is possible to use aeration in radial settling tanks, for rubbing mechanical particles from organic matter.

The vertical sump has the shape of a cylindrical tank made of metal (sometimes it is made square). The shape of the bottom is conical or pyramidal. can be classified based on the design of the intake device - central and peripheral. The most commonly used view with a central inlet. The water in the sump moves in a descending-ascending motion.

The principle of operation of the vertical sump

Water from the drains enters it through the upper part of the structure and moves down the central vertical pipe to the socket located there. Under the pipe is a shield that reflects and changes the trajectory of moving water from downward to upward. At the same moment, dispersed particles precipitate very intensively in the settling part. The flow of water that moves upwards moves through the edge for transfusion of water and enters the peripheral tray, where the clarified and purified water is collected. The sludge is periodically cleaned from the settling part with the help of a sludge pipeline.

A baffle in front of the ridges resists contamination from the waste that often floats to the top in the primary clarifier. After that, the contaminants are removed manually using a scraper or scoop and thrown into the well, which is located outside the design of the device.

The use of sedimentation tanks

A vertical sump is a device that is immersed in water to a maximum depth of 9 m. And if the groundwater is above this depth, it will be useless to use such a structure.

They are installed mainly in small wastewater treatment plants, the volume of which does not exceed 10,000 m2 per day.

Many factories and organizations prefer vertical settling tanks at their facilities, so there are a lot of their varieties - different in size and design.

Why a vertical clarifier is the right choice

They are easier to manage than horizontal ones, they have a simplified design. During normal operation, they can remove up to 40% of suspended solids from wastewater. Vertical sedimentation tanks are easier to install, and their cost is much lower than that of horizontal ones. The spillway along the perimeter has a large length and this allows you to significantly reduce the speed at which water moves, and this reduces the removal of suspension.

The principle of operation of sedimentation tanks - maintenance and operation

1. To prevent sediment from sliding to the central part of the bottom, during the development of the project and construction, it is necessary to make a slope to the horizontal surface below up to 50 degrees.
2. Carefully smooth the inside of the sump.
3. It is better to make the bottom conical, and not in the form of a pyramid. Because in the pyramid often a lot of precipitation accumulates in the corners, after which they begin to ferment.

But even after performing these actions, the most important problem will remain poor sediment slippage, which makes operation difficult. The fermented sediment will begin to produce gas, which will float to the surface of the primary sedimentation tank, and this in turn will increase the removal of suspended matter.

It is necessary to ensure that there is no crust on the surface, which is usually formed from substances consisting of fat, oil. It appears because of the garbage that floats on the surface. It is necessary that it enters the grease collector.

About precipitation

If your septic tank does not have a special bunker in which waste is collected, it must be made and installed as soon as possible using a pipe that must be connected to the sludge pipeline. On this pipe, you need to install a partition and open it as there is a large accumulation of debris. All collected waste is removed from the sump with a scraper or scoop, after which the partition is closed again.

Sediment that does not slide well to the bottom must also be pushed manually. Scoop or scraper can be made independently. The length of the handle must be longer than the length of the vertical sump. Due to the fact that the handle can be up to 9 meters long, together with the scraper, this design is very heavy and it is best not to get it out of the sump. The sediment must be manually pushed once per shift - at least every 12 hours. After the sediment is removed from the walls, the hydraulic elevator will turn on and the sediment will be disposed of.

What affects work efficiency

In order for the sump to work correctly, you need to take care of the optimal deepening of the vertical pipe through which the wastewater passes and the location of the shield, which will change the direction of water movement.

The length of the central pipe can be selected experimentally. Most often this happens if a lot of suspension is brought to the surface and it is necessary to select all the necessary characteristics based on the amount of these substances. Then it will be possible to make wastewater treatment more efficient and stable for a long time.

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